Instead of looking up the opcode twice (once for decode flags, once for
the big execution switch) look up both flags and function in the decode tables.
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_emulate.h | 1 +
arch/x86/kvm/emulate.c | 12 ++++++++++++
2 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index daf4477..f397b79 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -185,6 +185,7 @@ struct decode_cache {
bool has_seg_override;
u8 seg_override;
unsigned int d;
+ int (*execute)(struct x86_emulate_ctxt *ctxt);
unsigned long regs[NR_VCPU_REGS];
unsigned long eip;
/* modrm */
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index f3f6fd9..8b19da2 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -106,6 +106,7 @@
struct opcode {
u32 flags;
union {
+ int (*execute)(struct x86_emulate_ctxt *ctxt);
struct opcode *group;
struct group_dual *gdual;
} u;
@@ -120,6 +121,7 @@ struct group_dual {
#define N D(0)
#define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
#define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) }
+#define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
static struct opcode group1[] = {
X7(D(Lock)), N
@@ -349,6 +351,7 @@ static struct opcode twobyte_table[256] = {
#undef N
#undef G
#undef GD
+#undef I
/* EFLAGS bit definitions. */
#define EFLG_ID (1<<21)
@@ -1067,6 +1070,8 @@ done_prefixes:
c->d |= opcode.flags;
}
+ c->execute = opcode.u.execute;
+
/* Unrecognised? */
if (c->d == 0 || (c->d & Undefined)) {
DPRINTF("Cannot emulate %02x\n", c->b);
@@ -2631,6 +2636,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
special_insn:
+ if (c->execute) {
+ rc = c->execute(ctxt);
+ if (rc != X86EMUL_CONTINUE)
+ goto done;
+ goto writeback;
+ }
+
if (c->twobyte)
goto twobyte_insn;
--
1.7.1
--
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